I have done both ways with no noticable differences, but I normally just lightly place my fermenting bucket lid on the bottling bucket to make sure nothing nasty from the air gets into the beer. Don't place the lid on tight though.

__________________No yeast, no beer. No beer, no civilization. Therefore, we really have yeast to thank for all our modern-day conveniences and tasty beer

__________________"Sometimes when I reflect back on all the beer I drink I feel ashamed. Then I look into the glass and think about the workers in the brewery and all of their hopes and dreams. If I didn't drink this beer, they might be out of work and their dreams would be shattered. Then I say to myself, It is better that I drink this beer and let their dreams come true than be selfish and worry about my liver."